This invention relates to isolation pods or protective containment devices used to isolate patients and for their transport. This transportable containment device provides an impermeable barrier against chemical and biological agents by isolating the injured person within a plastic pressure-type filtered environment, and protects the persons doing the transporting as well as the patient. Preferably the isolation device is capable of being compactly stored and/or easily transported to a site for use in emergencies For instance, large containers or packs may store a large number of such containment devices for use by military people in the field against biological or other type of chemical hazards. On the other hand, individual isolation devices may be conveniently carried or stored on a paramedic emergency vehicle for use in emergencies when transporting one or more infectious patients or person that has AIDS or unknown infectious diseases that need to be controlled against transmission to the people doing the transporting.
The illustrated and preferred isolation and protective device is for use with a litter or stretcher, or other device, which allows the protective barrier to primarily be made of a thin plastic material which is collapsed for compact storage and expanded to receive a patient thereby providing a low-cost, disposable, containment device. For military applications, there is a need for a drag bottom for use with the isolation device so that the patient can be carried or dragged by a corpsman or a paramedic across a battlefield to a vehicle for later transport to a hospital, or the like. Another important consideration in the use of such a isolation device is that it be simple to use in times of extreme emergency or excitability, such that personnel opening the device and placing people into the containment device, may not be thinking as clearly as they would normally be thinking and such that untrained personnel may be pressed into service for placing patients in these isolation devices when there is a wide-spread, mass chemical or biological attack. Also, in the case of some diseases, such as hemorrhagic fevers, like Ebola or Marburg viruses, the patients may resist handling and there is a risk in contaminating the handlers unless the device is capable of being opened to a position in which it is very easy to place the patient inside. Further, when the patient is inside, it is important that the patient not be feeling claustrophobic and, therefore, it is desirable to provide the patient with a clear field of view, as well as to have air flowing the patient""s face so that the patient understands that he has plenty of air to breathe while being surrounded by the barrier housing.
With respect to air ventilation, when the ambient atmosphere about the patient is contaminated, the air being supplied into the containment device should be purified or filtered before flowing across the patient in the protective containment device. Stated differently, if the surrounding ambient atmosphere is contaminated, then it is desired than the patient be placed within the containment device, and that the air being supplied to the patient be purified and filtered before it is forced into the containment device. On the other hand, if the has an infectious disease that can be transported by air, then it is desired to have the air filtered or purified before it is discharged from the interior of the protective device into the ambient atmosphere. Also, there are a number of other considerations with respect to air flow that should be met to provide a viable air flow dynamics and an air-tight environment about the patient.
From a cost and a weight standpoint, there is currently provided a Vickers box device which typically cost $20,000 to $30,000 and is heavy, in that it weighs about 200 pounds unloaded. Such a device is very difficult to store in that it is bulky and not adapted for storage in large number or for use in the event of a biological emergency. In addition, it cannot be transported in various types of military evacuation vehicles or used with the common paramedic vehicles used by fire departments or other health safety units of a municipality. The Vickers box is intended for use for transporting victims of natural biological hazards, such victims may include persons who have been infected with Ebola or Marburg virus, anthrax or the like. The Vickers box comprises a relatively self-contained unit having an external frame with a biological hazard barrier comprising sheet polyvinyl chloride sheet suspended therefrom. The frame has a foot rest or step. A lower substantially oval loading port provides access to the interior through which a patient may be carried to rest on a stretcher-like structure. The barrier has a ventilation tube entering its foot end. Glove ports are formed on the sides of the frame thereof. A pass-through port extends through the barrier approximately near the center of the pod or about waist-high on the patient. There are pairs of glove ports on each side of the unit. Intravenous bags and the like may be suspended from the frame of the unit. An intravenous line may extend through a port in the side of the unit.
The use of flexible plastic, such as PVC for forming a isolation cylindrical plastic tube about a patient and for purifying the air being admitted into the enclosed volume is disclosed in U.S. Pat. Nos. 3,265,059 and 3,272,199. In these patents, a plastic polyvinyl chloride sheet, twice as long as the length of the patient""s bed, is hung on a series of slidable supports or by hangers slidable on an overhead external rod so that the medical person with his hands in the glove ports may administer to the patient by sliding the flexible sheet between the patient""s head and feet with the plastic sliding and the hangers sliding along the top support rail. In the U.S. Pat. No. 3,265,059, the sheet is folded with creases therein to facilitate its sliding. In the U.S. Pat. No. 3,272,199, air bearings at the end allow the telescoping of the plastic sheet over end units. The devices shown in these patents are for use with hospital beds or the like, and require large external frames having an overhead slide rod. Also, an excessive amount of plastic is used, that is, the plastic sheet is double the amount needed for the length of the patient or mattress. The devices proposed in these patents are bulky and are simply not compact for storage in large numbers to be ready for use in case of a biological emergency, nor are these devices adapted to be used with a litter for transport to or for use within evacuation vehicles, either of the military type or of a fire department type.
What is needed and desired is an inexpensive, easily-compatible and stored isolation device which can be held in inventory by military or civilian defense organizations at various locations for quick access. Also, there is a need for inexpensive and compact isolation devices for inventory by fire departments or other evacuation municipal units where they may be transporting people with airborne infectious diseases or fluid transmitted diseases such as AIDS or hepatitis and where there is bleeding. A large amount of money is spent cleaning emergency vehicles after the transporting of people who are bleeding and who could possibly have AIDS, infectious hepatitis, etc. The amount of time consumed in cleaning such vehicles; and the resultant hazards involved with any improper cleaning to the paramedics and to subsequent patients is a problem. It would be better if the patient could be placed in the isolation containment device and transported without contaminating the evacuation vehicle such that the isolation device, or pod, itself could be disposed of by burning or by cleaning in some manner for reuse.
While the aforesaid copending application describes and illustrates an embodiment in which there is provided a drag bottom and a stretcher, there are other instances where a litter need not be used and that the patient is fully ambulatory and still needs the protection of a containment device. Thus, the present invention is directed to providing the need for such a isolation or containment pod device for an ambulatory or non-ambulatory patient.
This invention relates to a new and improved collapsible, transportable personnel isolation apparatus which minimizes the biological or chemical hazards to or from a patient within the protective containment apparatus.
The collapsible, transportable containment apparatus may be used with ambulatory patients in one embodiment or used with non-ambulatory patients in another embodiment. The containment device is preferably inexpensive in the sense that it can be purchased and stored by the military and/or by fire or civil defense departments in large quantities for use in terrorist attacks and, after use, may be disposed of by burning or the like. The collapsible, compact nature of the protective containment device allows it to be stored in large numbers on pallets or to require such a small storage space that it can be stored on a civilian or miliary evacuation vehicle and be ready for use when needed.
In the preferred embodiment, the protective containment device is provided with various ports, for example glove ports, pass-through ports, access ports for electrocardiac leads, a stethoscope, or a suction pump line, or infusion line ports for infusion lines that are connected to an external intravenous infusion device. Other ports may be provided for extending a ventilation tube to an airway made into the patient""s trachea to intubate the patient. Preferably, sufficient glove ports are provided to allow medical personnel access to the patient""s head, chest, abdomen and lower extremities.
In one embodiment of the invention, the isolation device may be used with or as a litter or stretcher with the patient being prone within a thin, plastic housing which is reinforced by strategically-placed straps that will carry the weight of the patient without tearing the plastic housing which, by itself, lacks sufficient strength to support the weight of the patient. Also, in accordance with the preferred embodiment of the invention, a detachable drag bottom or base may be attached to the bottom of the flexible housing to allow dragging of the containment device along the ground for use in situations that necessitate such a the drag bottom was an integral base sheet that is thicker than the flexible housing wall; and the base sheet contained a plurality of handholds therein for carrying the isolation device with the patient therein.
In accordance with another aspect of the invention, the protective isolation device is easily used by trained medical personnel, as well as untrained or unskilled people, because the device is preferably in the shape of a sleeping bag or clam shell having two halves that are easily opened by operation of a closure device, preferably an airtight zipper. The halves are readily laid open and apart to allow the medical personnel to lower the patient onto the lower half in the proper position. In the preferred embodiment, a patient""s silhouette is provided on the bottom half showing the location of the patient""s head and upper body so that medical personnel, which may be operating under extreme duress or very adverse conditions, can quickly place the patient in the desired orientation. Some patients infected by hemorrhagic fevers, such as Ebola or Marburg virus, may resist handling and others may be thrashing about for various reasons. Preferably, restraints are provided to restrain the patient at the desired position with the protective containment housing for use, if they are needed.
Another important aspect of the invention is to alleviate the patient""s apprehension or claustrophobic feeling while within the isolation device. To this end, the patient has a clear view through the transparent, plastic housing and a noticeable flow of air passes across the patient""s head. Also, the patient will not feel so encapsulated because this flowing pressurized air, as well as stays or supports, will keep the plastic housing spaced upwardly from contacting with the patient""s skin and wounds so that the wounds can be more easily treated. The preferred airflow rate across the patient is 4-6 cfm at a pressure of 4 inches of water, which is needed to prevent buildup of carbon dioxide about the patient""s head and to remove moisture that would fog the interior of the plastic housing and thereby interfere with the patient""s view of the exterior, as well as the view of the medical personnel into the interior of the containment device.
In accordance with the invention, the dynamics of the airflow and the tightness of the housing against air leakage is such that upon stopping the airflow into the housing, the air pressure within the housing will not decrease by more than twenty percent over a five minute period. Unidirectional airflow valves at the air inlet and exhaust ports prevent air outflow through the inlet and/or the wrong direction through the exhaust ports; and the use of an airtight zipper allows meeting of this air leakage standard.
Tn accordance with another important aspect of the invention, the air is preferably purified prior to being flowed into the containment device and prior to being exhausted into the ambient atmosphere. In crisis situations, the medical personnel may be unsure as to whether it is the ambient atmosphere that is contaminated or it is the atmosphere within the containment device that is contaminated. In the aforesaid copending patent application, the blower and filter unit could be connected to one end of the containment device housing to blow purified air into the patient within protective housing if the medical personnel thought the ambient air was contaminated. On the other hand, if the medical personnel thought that the patient had an infectious disease or other air-born contaminants, then the blower and filter unit was connected to the other end of the protective housing and negative pressure was provided by the blower unit to suck air from the housing. While such arrangement may be used, it is preferred to provide one-way flow devices and blower/purifier units at both ends of the protective housing to provide a unidirectional flow of purified air into and from the protective housing.
In some emergency situations, patients may have extreme burns over large portions of their body, and it may be desirable to place them in a hyper oxygenated atmosphere where the excess oxygen assists in the healing process and may adversely affect bacteria or burn contaminants. The contaminant apparatus of the present invention, with suitable safeguards with respect to fire or the like could be used to receive the hyper oxygenated air and to isolate the patient, particularly during transport from the burn site to a burn treatment center. In such instances, the medical manifold would be equipped with a grounding strap that would prevent static electricity buildup between the patient and the static plastic enclosure.